1. Field of the Invention
The present invention relates to a method for measuring the dimension or clearance of a gap of a carrying path including a magnetic head through which a card is passed when a passenger sets the card on an automatic ticket checking and collecting machine at a train station or in an one-man control bus, or on other similar machine. The present invention covers a reading unit of credit cards and prepaid cards. Further, the invention also relates to a gap clearance measuring laminated member and a gap clearance measuring system directly used for implementing the foregoing method.
2. Description of Related Art
An automatic ticket examining (or checking and collecting) machine at a train station or in a bus, a telephone adapted for telephone cards, or a reading device of credit cards or prepaid cards reads the information stored in a magnetic card or writes new data to the card by passing it between a carrying roller and a magnetic head. It is necessary to properly control the contact pressure of the magnetic head with respect to the card so as to enable the magnetic head to perform accurate reading and writing.
For cards other than magnetic cards, it is required to control the gap relative to a reading head to a proper dimension i.e. gap clearance. For this purpose, it is necessary to precisely adjust the gap formed between the magnetic head or the reading head and the carrying roller facing against the magnetic head or the reading head in accordance with the predetermined thickness of a card which passes therethrough. In order to adjust the gap clearance, conventionally, the machine has been disassembled and a thickness gauge has been applied or the card has been repeatedly passed through the gap until the gap is properly adjusted.
The aforesaid conventional method in which the card is repeatedly passed through the gap to achieve proper adjustment of the gap has been posing a problem in that it takes much effort and time.
Especially in the case of the automatic ticket examining machines with an extremely high operation frequency, maintenance staff must check them every morning, and the problem described above has been serious because of the need of much time and effort, that is, low efficiency. In addition, there has been another problem in that the gap adjustment depends on the experiences and intuition of each maintenance person, so that the adjusted gap tends to be nonuniform or inaccurate.